Portable Nucleic Acid Extraction System Developed For POC Diagnostics

A minimally instrumented sample preparation technology yields a purified and thermally stabilized nucleic acid sample that eliminates the cold chain without reducing sensitivity or an increase in downstream processing infrastructure.

Biomedical engineers at Boston University (MA, USA) have developed a whole blood compatible, enzyme-free, ambient temperature, low-pressure nucleic acid extraction process that enables the creation of a completely powerless nucleic acid sample preparation technology. This technology will allow, for example human immunodeficiency virus (HIV) viral load monitoring in low resource areas.

A novel hybrid alcohol precipitation and solid phase extraction process has been presented, utilizing glycogen carrier particles to increase the effective hydrodynamic radius of precipitated nucleic acids aggregates, and a thermally polymerized acrylate based solid phase as a weir for analyte capture. An air pressure driven mechanical system was developed to perform this process in a semiautomated fashion, in order to insulate the process from variations in operator technique. Together, they form the System for Nucleic Acid Purification (SNAP).

The portable system for centrifuge-free room temperature nucleic acid extraction from 70 μL of whole blood uses only thermally stable reagents compatible with storage and transport in low resource settings. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analysis of simulated samples demonstrate a lower limit of detection of 1,000 copies per mL, with the ability to detect differences in viral load across four orders of magnitude.

The device weighs less than 1.36 kg and is capable of extracting HIV-1 viral ribonucleic acid (RNA) directly from virions in whole blood in less than 35 minutes. Samples are stabilized on detachable cartridges, which can be eluted either at the point of care, or transported to a centralized laboratory for further analysis. The study was published on May 13, 2013, in the journal Analytical Methods.

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